diff --git a/packages/cli/src/commands/layout-audit.browser.js b/packages/cli/src/commands/layout-audit.browser.js
index 14ee9ed943..3d83317c2d 100644
--- a/packages/cli/src/commands/layout-audit.browser.js
+++ b/packages/cli/src/commands/layout-audit.browser.js
@@ -2209,9 +2209,11 @@
   // Canvases that drew WebGL while hidden since the last audit, judged when the draw happens; the author's own
   // hf-seek loop decides what draws.
   const webglDraws = (window.__hyperframesWebglDraws ??= new Set());
+  let judgedThisSample = new WeakSet();
   const drawGate = Symbol.for("hyperframes.webglDrawGate");
   window.__hyperframesRecordWebglDraw = (canvas) => {
-    if (!canvas || webglDraws.has(canvas)) return;
+    if (typeof canvas?.closest !== "function" || judgedThisSample.has(canvas)) return;
+    judgedThisSample.add(canvas);
     if (canvas.closest(RUNTIME_HIDDEN_CLIP) || canvas.checkVisibility?.() === false) {
       webglDraws.add(canvas);
     }
@@ -2230,7 +2232,9 @@
       const draw = proto[method];
       if (typeof draw !== "function") continue;
       proto[method] = function (...args) {
-        if (!window[drawGate]?.skip) window.__hyperframesRecordWebglDraw(this.canvas);
+        try {
+          if (!window[drawGate]?.skip) window.__hyperframesRecordWebglDraw(this.canvas);
+        } catch {}
         return draw.apply(this, args);
       };
     }
@@ -2239,6 +2243,7 @@
   function inactiveWebglIssues(root, time) {
     const drawn = [...webglDraws].filter((canvas) => canvas?.isConnected);
     webglDraws.clear();
+    judgedThisSample = new WeakSet();
     return drawn.map((canvas) => {
       const scene =
         canvas.closest("[data-composition-id]:not([data-width])") ??
diff --git a/packages/cli/src/commands/layout-audit.browser.test.ts b/packages/cli/src/commands/layout-audit.browser.test.ts
index 14d282a247..42d0913ee3 100644
--- a/packages/cli/src/commands/layout-audit.browser.test.ts
+++ b/packages/cli/src/commands/layout-audit.browser.test.ts
@@ -1352,6 +1352,45 @@ describe("layout-audit.browser coordinate-frame findings", () => {
       expect(runAudit().filter((i) => i.code === "webgl_draws_while_inactive")).toHaveLength(1);
       expect(runAudit().some((issue) => issue.code === "webgl_draws_while_inactive")).toBe(false);
     });
+
+    function installFakeWebgl(): { drawn: unknown[]; context: { canvas: unknown } } {
+      const drawn: unknown[] = [];
+      class FakeContext {
+        canvas: unknown;
+        drawArrays(...args: unknown[]) {
+          drawn.push(args);
+        }
+      }
+      (window as unknown as Record<string, unknown>).WebGLRenderingContext = FakeContext;
+      return { drawn, context: new FakeContext() };
+    }
+
+    it("lets an OffscreenCanvas context draw, and reports nothing for it", () => {
+      const { drawn, context } = installFakeWebgl();
+      mountScenes(true);
+      context.canvas = { width: 64, height: 64 };
+
+      (context as unknown as { drawArrays(mode: number): void }).drawArrays(4);
+
+      expect(drawn).toEqual([[4]]);
+      expect(runAudit().some((issue) => issue.code === "webgl_draws_while_inactive")).toBe(false);
+    });
+
+    it("checks a canvas's visibility once per sample, however many draws it makes", () => {
+      const { context } = installFakeWebgl();
+      const canvas = mountScenes(false);
+      const closest = vi.spyOn(canvas, "closest");
+      context.canvas = canvas;
+
+      for (let i = 0; i < 50; i++)
+        (context as unknown as { drawArrays(mode: number): void }).drawArrays(4);
+      expect(closest).toHaveBeenCalledTimes(1);
+
+      runAudit();
+      closest.mockClear();
+      (context as unknown as { drawArrays(mode: number): void }).drawArrays(4);
+      expect(closest).toHaveBeenCalledTimes(1);
+    });
   });
 
   describe("canvas_content_at_edge", () => {